1. Field of the Invention
The invention relates to a semiconductor device and a manufacturing method thereof, particularly to a package type semiconductor device and a manufacturing method thereof.
2. Description of the Related Art
CSP (Chip Size Package) has been pursued as a package type semiconductor device. The CSP means a small package having almost the same outside dimensions as those of a semiconductor die packaged in it.
Conventionally, a BGA (Ball Grid Array) type semiconductor device has been known as a kind of CSP. In this BGA type semiconductor device, a plurality of ball-shaped conductive terminals made of a metal such as solder is arrayed in a grid pattern on one surface of the package, and electrically connected with the semiconductor die mounted on the other side of the package. A manufacturing method of the BGA type semiconductor device of the conventional art will be described with reference to drawings next. FIG. 6 is a cross-sectional view showing the manufacturing method of the semiconductor device of the conventional art. FIG. 7 is a cross-sectional view showing the semiconductor device and the manufacturing method thereof of the conventional art.
First, as shown in FIG. 6, a pad electrode 51 is formed on a front surface of a semiconductor substrate 50 formed with an electronic device (not shown), extending from the electronic device. A support substrate 60 is further formed on the front surface of the semiconductor substrate 50. This support substrate 60 is made of, for example, a silicon substrate, a glass substrate, a ceramic substrate, or a metal substrate, supporting the semiconductor substrate 50 and preventing the semiconductor substrate 50 from cracking or warping. Then, a back surface of the semiconductor substrate 50 supported by the support substrate 60 is ground. The semiconductor substrate 50 is thinned to have a predetermined thickness by this backgrinding process.
Then, the semiconductor substrate 50 is formed with a via hole 52 penetrating from its back surface to the pad electrode 51. A wiring layer 53 is formed in the via hole 52, being electrically connected with the pad electrode 51. Between the semiconductor substrate 50 and the wiring layer 53, an insulation film (not shown) is formed. A protection layer 54 is formed on the wiring layer 53 so as to partially expose the wiring layer 53. On the exposed wiring layer 53, a conductive terminal 55 is formed, which can be connected with an external printed circuit board and so on.
Next, as shown in FIG. 7, dicing is performed along a dicing line (not shown) to separate the semiconductor substrate 50 into semiconductor dies 50A. Then, the support substrate 60 attached to the front surface of the semiconductor die 50A is peeled off or removed, thereby completing the package type semiconductor device. The relevant technology is disclosed in the Japanese Patent Application Publication No. 2003-309221.
In the manufacturing method of the package type semiconductor device described above, however, the support substrate 60 used for supporting the semiconductor substrate 50 in the backgrinding process or the forming process of the via hole 52 need be removed from the semiconductor die 50A after the processes. This causes a problem of making a manufacturing method of the semiconductor device complex and increasing a manufacturing cost.
Furthermore, on the front surface of the semiconductor device after the support substrate 60 is removed, the semiconductor die 50A is not sufficiently protected (from moisture permeation from outside and the like). This causes a problem of decreasing reliability of the semiconductor die. Alternatively, the front surface of the semiconductor die 50A (or the semiconductor substrate 50) is processed again for protecting the semiconductor die 50A. This causes a problem of making the manufacturing method complex and increasing the manufacturing cost.